Perlͷ࣌ؒ͸ϞδϡʔϧͰ Perlएखͷձ 2020-07-01 @koluku

ࣗݾ঺հ • koluku ʢίϧΫʣ • एख, Perlܦݧ͸2ϲ݄, ొஃܦݧແ͠ • Python/Go͕ϝΠϯ

࿩͢͜ͱɾ࿩͞ͳ͍͜ͱ • ࿩͢͜ͱ • ࣌ؒͷ੍ޚͷ͋Ε͜Ε • Time::Pieceָ͕ͩΑ • ࿩͞ͳ͍͜ͱ • ࣮૷ͷ࿩

$^T • ʮϓϩάϥϜΛ࣮ߦ։࢝ͨ࣌͠ࠁΛɺلݩ (1970೥ͷ࢝Ί) ͔Βͷඵ ਺Ͱ ࣔͨ͠΋ͷͰ͢ʯ • لݩ (1970೥ͷ࢝Ί) ͬͯԿΑʁ

time • ʮ΄ͱΜͲͷγεςϜͰ͸لݩ͸UTC1970೥1݄1೔00:00:00Ͱ͢; ಛ௃తͳྫ֎ͱͯ͠͸ɺݹ͍MacOSͰ͸ϩʔΧϧλΠϜκʔϯͷ 1904೥1݄1೔00:00:00Λلݩͱͯ͠࢖͍·͢ɻʯ • UTC1970೥1݄1೔00:00:00͸͍ΘΏΔUNIX࣌ؒ • UTC1904೥1݄1೔00:00:00͸͏Δ͏೥ͷྫ֎ճආͷͨΊͷ೔෇ • 1904೥͔Β2096೥·Ͱ͏Δ͏೥͸ଘࡏ͢Δ

$^Tͱtime • ͲͪΒ΋γεςϜ࣌ؒΛฦ͢ͷͰ࣮࣭ಉ͡ • ݱࡏ࣌ؒΛ஌Ζ͏ʹ΋UNIX࣌ؒʢඵ਺ʣͰฦ͞ΕΔͷͰී௨ʹ͸ѻ ͑ͳ͍ • ͦ͜ͰlocaltimeͱgmtimeΛ࢖͏

localtime • ʮtimeؔ਺͕ฦ࣌͢ࠁΛɺϩʔΧϧͳλΠϜκʔϯͰଌͬͨ࣌ࠁͱ͠ ͯɺ9ཁૉͷ഑ྻʹม׵͠·͢ɻී௨͸ɺҎԼͷΑ͏ʹͯ͠࢖͍·͢:ʯ • $wday͸೔༵೔Λ0ͱ༵ͨ͠೔ɺ $yday ͸ͦͷ೥ͷԿ೔໨͕ؼͬͯ͘ Δ • εΧϥʔͷͱ͖ʹѻ͏ͱจࣈྻͰؼͬͯ͘Δ • ศརʂ

gmtime • localtimeͩͱϚγϯͷ࣌ؒʹґଘ͢ΔͨΊ೔ຊͩͱGMT+9:00 • άϦχοδඪ४࣌ʹ໭͢ʹ͸-9࣌ؒ͢Δඞཁ͕… • localtimeͱಉ͡࢓૊ΈͰάϦχοδඪ४࣌Λѻ͏gmtime͕͋ΔͷͰ ҆৺ʂ

localtimeͱgmtimeͷ᠘ • ʮ$year ͸ 1900 ೥͔Βͷ೥਺Λ࣋ͪ·͢ɻʯ • ਓ͕ؒಡΈ΍͍͢Α͏ʹԼೋܻͰ൑அͰ͖Δ։࢝஍఺ͷͨΊ • ͍ΘΏΔPOSIX४ڌ • ೥͚ͩͰݟΔͱ3ύλʔϯ͋Δ

localtimeɺศརʹ͸ศརͳΜ͚ͩͲ… • ਺஋৘ใ͔͠ͳ͍͔Βѻ͏ʹ͸݁ہؔ਺Λ࡞Δඞཁ͕͋Δ • ศརϝιου͕ੜ͑ͨΦϒδΣΫτͰฦͯ͠΄͘͠ͳ͍ʁ

Time::Piece • Timepiece͸࣌ܭͱ͍͏ҙຯ • localtime, gmtime͕Time::PieceΦϒδΣΫτͰؼͬͯ͘Δ • ཉ͍͠ػೳ͸େମἧ͍ͬͯΔ

Time::PieceͰՃࢉɾݮࢉ • Time::SecondsͰ1෼ʢONE_MINUTEʣͳͲͷఆ͕ٛݺͼग़ͤΔ • Time::PieceʹTime::SecondsͰՃࢉɾݮࢉ͢Δ͜ͱ͕Ͱ͖Δ • localtime + ONE_DAY • Time::Pieceಉ࢜Ͱݮࢉ͢ΔͱTime::SecondsͰؼͬͯ͘Δʢඵ਺ʣ • localtime - gmtime

Time::PieceͰൺֱ • Time::Pieceಉ࢜Ͱൺֱ͢Δࣄ΋Ͱ͖Δ • return if (localtime - gmtime == ONE_HOUR * 9); • Time::Pieceศར͗͢ͳ͍ʁ

Ͱ΋Ͳ͏΍ͬͯՃࢉ΍ൺֱΛͯ͠Δʁ • ͪΐͬͱدΓಓ • Α͘ߟ͑ͨΒTime::Piece͸ΦϒδΣΫτ͔ͩΒී௨ͷԋࢉࢠͰܭࢉ Ͱ͖Δͷ͸͓͔͍͠

͜͏͍͏ͱ͖͸ίʔυΛಡΉͷ͕ૣ͍ • ͱ͏͍͏͜ͱͰmeta::cpan͔ΒBrowseͰίʔυΛݟͯΔͱ Time::Seconndsʹoverloadͱ͍͏໊લ͕ग़ͯ͘Δ

overload • perldoc.jpΛݟͯΈΔͱʮPerl ͷԋࢉࢠͷΦʔόʔϩʔυΛߦ͏ύο έʔδʯͱ͋Δ • ͭ·Γࢉज़ԋࢉࢠ΍ൺֱԋࢉࢠΛผͷؔ਺ʹ্ॻ͖Ͱ͖Δ • Time::SecondsͰ+ԋࢉࢠͷ৔߹͸ࠨӈ͔Β஋Λऔͬͯؔ਺ʹೖΕͯ ܭࢉͨ͠΋ͷΛฦ͍ͯ͠Δ • ͳΔ΄ͲͶ

Ͱ΋େମѻ͍͍ͨͷ͸MySQLͷͱ͖… • ࿩͸໭ͬͯɺ࣌ؒͱ͍͑͹MySQLͰͷѻ͍͸ͳ͔ͳ͔໘౗ • fracʢখ਺఺ҎԼʣ͕௥Ճ͞Ε͍ͯΔ͜ͱ΋͋Δ • DATETIMEͱTIMESTAMP͸ಉ͡ϑΥʔϚοτͰ΋ɺ • αϙʔτ͞Ε͍ͯΔൣғ͕ڱ͍, DATETIME͸݄ɾ೔ʹ00Λڐ༰ • ಉ͡஋Ͱ΋ҧ͏஋Ͱొ࿥͞ΕΔ͕࣌͋Δ • ͜Μͳͷී௨ʹѻ͍ͨ͘ͳ͍ʂ

Time::Piece::MySQL • Time::Pieceͷ֦ுϝιου • Time::Piece->mysql_dateͰMySQLͷDATEܕʹม׵ • Time::Piece->from_mysql_date($datetime)ͰMySQLͷDATEܕ͔Β Time::PieceΦϒδΣΫτʹม׵ • ͜ΕͰMySQLͰͷ࣌ؒͷॲཧʹۤ࿑͢Δ͜ͱ͸ͳ͘ͳͬͨ…ʂ

΍ͬͨʂੈքʹฏ࿨͕๚ΕͨʂͰ΋… • ϛϦඵɾϚΠΫϩඵͷѻ͍͸Ͳ͏͢Δͷʁ • ϓϩάϥϜͷ࣮ߦ࣌ؒΛѻ͍͍ͨΜ͚ͩͲ • Q: Ұఆ࣌ؒॲཧΛsleepͤ͞Δʹ͸ • ೔෇Λ࿨ྐྵʹม׵͍ͨ͠ • ೔෇ͷൣғʹ͋Δ͔Ͳ͏͔Λָʹܭࢉ͍ͨ͠ • ೔ຊҎ֎ͷ࣌ࠁΛϩέʔϧ͍ͨ͠ • ҧ͏ϩέʔϧ࣌ؒͲ͏͠Ͱࠩ෼Λग़͍ͨ͠ • etc…

͝ΊΜʂLT͡Ό࣌ؒ଍Γͳ͍͔Β ࣗ෼Ͱௐ΂ͯʂ